Nowadays, both infrared imaging technology and infrared temperature measurement technology are applied to the technical field of automatic forest fire alarm system and their related fields. The way to achieve it is to use an infrared camera as a surveillance camera platform to receive infrared rays from a targeted object and to transform the infrared radiation from the surface of the targeted object into video signals to form video images; then a specific software analyses and captures the hottest temperature spot of the said video images; finally, the system compares the hottest temperature spot with the preset alarm temperature and alarms while the hottest temperature spot surpasses the preset temperature spot.
The present infrared excessive temperature surveillance and alarm technology achieves imaging and alarm through comparing the variation of the temperature of the monitored region and captures the hottest spot of the screen. When the device detects the hottest spot which is higher than that of the preset parameter, the alarm will yield warning signals.
However, the monitoring method for forest fire detection and alarm has its own intrinsically distinction from general environmental surveillance. The hottest temperature alarm arithmetic existed does not suffice the requirement of forest fire detection. The main reasons are as follows: 1. the long range and extensive region of monitoring for forest fire detection call for extremely severe technical requirement of infrared monitor equipment. But due to the remote distance, there are possible unavoidable temperature measurement errors which could lead to the incorrect detected hottest temperature value. 2. The environment for forest fire surveillance is very complicated. Owing to different seasons, day/night temperature differences, North or South latitude and the varieties of geography and topography, the regional or the whole climate of the monitored area thus become unpredictable and filled with variables, so that it is difficult to deduce or generalize its changing trends. It is supposed that this should directly leads to the oscillation of the parameter which can be used as the temperature alarm because the referenced figure would be affected to be plus or minus due to the change in temperature or climate caused by different seasons, alternate day and night, regional latitudes. However, since the particular figure is not easy to be set randomly, it results in the difficulty in precise temperature measurement and alarm by infrared monitoring devices.